This invention relates generally to the obtaining of samples for purposes of identification or analysis and relates, more particularly, to a means for collecting such a sample from a source.
The class of equipment with which this invention is utilized includes diagnostic equipment, such as a mass spectrometer, used for characterizing (e.g. identifying or analyzing) materials. It is not uncommon, for example, that military or rescue personnel occasionally come across material, such as a liquid contained in an unlabeled drum, that cannot be readily identified. Due to the chances that such material may be harmful or toxic to humans, it is important that the material be correctly identified or characterized before it is handled. For purposes of identifying the material as quickly as possible, the diagnostic equipment to be employed, such as a mass spectrometer, is commonly mounted upon a mobile unit and driven to the site where a material which is desired to be identified is located.
There is normally associated with such diagnostic equipment a probe to which a sample amount of the material to be identified is introduced to the equipment. The diagnostic equipment of the class with which this invention is concerned is normally adapted to analyze and identify materials when in the vapor state. Therefore, there is typically associated with the probe a heater so that when a liquid sample of the material to be identified is placed adjacent the probe, the heater vaporizes (at least some of) the liquid sample, and the vaporized sample is, in turn, conducted to the diagnostic equipment for identification or analysis.
Heretofore, an amount of the material to be identified or analyzed has first been collected upon the surface of a wheel having a rubber-like periphery, and the surface of the wheel, with an amount of material clinging thereto, is thereafter placed into engagement with the probe. In this connection, the periphery of the wheel is initially moved (e.g. rolled) across or dipped within the material to be identified or analyzed so that an amount of the material adheres to the peripheral surface of the wheel. The surface of the wheel is then pressed into engagement with the probe so that a sample amount of material which clings to the peripheral surface of the wheel is transferred from the wheel surface to the probe.
Such a prior art technique of transferring an amount of material from a source to the diagnostic equipment is limited in that volatile compounds (which may comprise the material to be analyzed) can dissipate very quickly from the wheel surface so that very little sample is ultimately transferred from the wheel surface to the diagnostic equipment (e.g. a mass spectrometer); and if the amount of sample which is conducted from the wheel surface to the diagnostic equipment is too small, then the signal which is generated by a signal-generating means of the diagnostic equipment from the sample might not be strong enough to accurately identify or characterize the material. By comparison and in the case of materials which are comprised of less volatile compounds, too much material could be transferred from the wheel surface to the diagnostic equipment and ultimately degrade the signal-generating means of the equipment.
It would be desirable to provide an improved means for collecting an amount of sample material from a source and for transferring the collected sample to a probe associated with diagnostic equipment for purposes of identifying or analyzing the sample.
Accordingly, it is an object of the present invention to provide a new and improved means and method for collecting a sample from a source of material to be identified or analyzed and transferring the collected sample to the probe associated with diagnostic equipment of the aforedescribed class.
Another object of the present invention is to provide such a collection means whose use is less likely to effect the transfer of either too much or too little an amount of the sample to the diagnostic equipment for identification or analysis.
Still another object of the present invention is to provide such a collection means which is well-suited for collecting a sample amount of material, whether the material is relatively volatile or not very volatile.
Yet another object of the present invention is to provide such a collection means which is highly sensitive to the sample being collected, contributes to a more accurate identification or characterization of the sample, is relatively easy to use, provides greater safety for the operator, and is less expensive to use than is the wheel of the prior art technique described above.
A further object of the present invention is to provide such a collection means which is uncomplicated in structure, yet effective in operation.